Ruler



Dec. 5, 1939.lc, H. LITTLE I 2,182,027

RULER Filed Feb. 3,- 1956 mmm , '7.5 7 F/G. 2 /=/G.l 3 op g? 561.4 FG' 5INVENTOR. CHARLES H f7-71E M140@ fsm ma AT TORNEYSW n iPatented Dec. 5,1939 signor of one-tenth to Charles Hubbard Little, Cleveland Heights,Ohio Application February 3, 1936, semi No. 62,144

1 Claim.

The present invention relates to drafting devices or instrumentsemployed. in drafting, and more particularly to a drafting ruler, eitherscale or straight edge.

Numerous attempts have been made in the past, as evidenced by my ownprior art patents and otherwise, to produce a stiff, durable, light,easily readable ruler for drafting purposes which would not warp andwhich would be otherwise satisfactory. At a very great expense I havemade hundreds of experimental rulers from Celluloid, various kinds ofWood treated in numerous ways, different metals and alloys, speciallydrawn tubing or bars, and various kinds of stampings. In additionthereto, I have made numerous compound rulers comprising metallic andnon-metallic coresencased or enclosed in Celluloid, etc". But prior tothe present inven- Ifion neither I nor others working along the same 20line have been able to produce an entirely satisfactory drafting rulerembodying the aforesaid advantages. l

An object ofthe present invention is the provision of a novel draftingdevice or ruler which will be light, stiff, durable, and easily readablein t'ne event graduations are marked thereon, which will not warp, andwhich will be otherwise satisfactory for the purpose intended.

Another object of the invention is the provision of a novel draftingdevice or ruler comprising a metal body having edge strips formed of aplastic molded thereon and mechanically interlocked therewith.

Other objects and advantages of the present invention'will be apparentto those skilled in the art to which the invention relates from thefollowing description of the preferred embodiments thereof, describedwith reference to the accompanying drawing forming a part of thisspecification, in which similar reference characters designatecorresponding parts throughout the several views, and in which Fig. 1 isa plan viewof a drafting device or ruler embodying the presentinvention.

Fig. 2 is a fragmentary perspective view showing the ruler in section onthe line 2-2 of Fig. 1.

Figs. 3 to 8 inclusive are views similar to Fig.'

2, each showing a different modified construction of the ruler shown inFigs. 1 and 2, with the exception of Fig. 4a which is an enlargedpartial section of the ruler shown in Fig. 4.

Figs. 9, 1,1, 13 and 15 are fragmentary perspective views of one end ofa drafting device or ruler similar to that shown in Fig. 6, each figureshowing a different modified construction thereof.

Fig. 10 is a section on the line Ill-I0 of Fig. 9.

Fig. 12 is a section on the line I2-I2 of Fig. 11.

Fig. 14 is asection on the lline I4-I4 of Fig. 13.

Fig. 16 is a section on the line lli- I6 of Fig. 15.

The drafting ruler A shown in Fig.A 1 is of the type ordinarily referredto as a drafting scale and is especially adapted for use with draftingmachines of the type shown in either of my United States Patents No.1,909,289 or 1,909,291. Theparallel or 'ruling edges of the scale arebeveled as clearly shown in Fig. 2, and provided with suitablegraduations, etc. Provision is made for chucking the device to the chuckor ruler supporting arm of a drafting machine, by providing oppositerends thereof with chucks I0 adjustably secured thereto as by screws Il.The two chucks shown permit the ruler to be reversed, that is, eitherend may be chucked to the chuck-arm of the drafting machine, as is theusual practice.

The chucks are preferably made of duralumin 20 and given an oxidecoating by a well known elec- `trolytic process which gives the surfacea coating that is free from glare and has a pleasing appearance-andwhich will not soil the v,drawing paper or surface.

In the embodiment of the invention shown in Figs. 1 and 2, the draftingdevice or ruler A is made entirely of a polymerization product of avinyl compound, such as vinyl chloride, vinyl acetate, or vinyl benzine.These plastics have characteristics which adapt them peculiarly to thepresent use Rulers made therefrom do not shrink or warp, are light inWeight, durable, and easy to clean. The vinyl acetate is permanentlynearly Water white and when the ruler is made therefrom the edges can bereadily made transparent, in which event the graduations, if employed,may be placed on the under side. Commercially known plastics sold underthe trade names Vinolyte, Vietro, Galva, etc., which are for the mostpart polymerization products of vinyl compounds, are suitable for thepresent Aio ' 1f .gi-'eatersunness ie desired in the drafting ruler or.device it can be obtained by providing the same with a metal core. Sucha construction is'shown'in- Fig. 3 which shows a drafting rulerdesignated enerally by the reference .char- I be made in one piece, asshown, or comprises a plurality of pieces or members.

` Instead of the entire ruler -being made ofthe vinyl compound asillustrated in Fig. 1, or provided with a core as illustrated in Fig. 3,it may comprise a metal body, preferably duralumin, provided .with edge"stripslpreierably made of a polymerization product of a vinyl compound'molded thereto. In this event the ruler is prei?-v erably soconstructed that there is a mechanical interlock between the edge stripor strips and thev metal body. Fig. 4 shows a ruler designated generallyby the reference character C comprising edge strips I6 and I1 formed ofa plastic and molded in position on the beveled edges of the bodyportion I8 and interlocked therewith by a plurality of rectangulartongues or projections I9 and 20 at right angles to each other formedintegral with the edge. strip and'engaging within suitable grooves inthe upper side of the ruler body, anda tongue 2| also on the edge stripwhich projects inwardly and upwardly into an inclined groove in theunderside vof the body portion I8. The aforesaid construction provides amechanical interlock between the ruler b ody and the edge strips so asto prevent movement in a number 'of directions.

Fig. 5 shows a ruler D wherein the edge strips 23 and 24 are connectedto theruler body 25 by a single dovetail tongue and groove supplemented.by a rectangular tongue and groove adjacent the ruling edge of theplastic edge strip. The body portion 25 has achannel formed in theunderside thereof for the purpose of reducing the weight of the ruler.Fig.. 6 shows a ruler E wherein the edge strips 26 and 21 are connectedto the`ruler body 28V by a Aplurality of dovetail grooves. As shown inFig. 7 the entire beveled portions of the ruler F are made of edgestrips 30 and 3| likewise formed of a plasticA and me- I chanicallyinterlocked with the ruler body 32 by a single dovetail groove. Fig. 8shows a ruler G, the construction of which is similar to that shown inFig. 7 except a straightedge type of ruler is illustrated instead of thescale type shown in the other'gures.

In the foregoing figures the mechanical interlock between the edgestrips and the body portion consist ofv tongues `and grooves runninglongitudinally of the ruler, thereby holding-the strips. againstmovement particularly crossw'ise ofthe ruler body, but it will beapparent that other forms of mechanical interlock can be employed eitheralone or to supplement those shown. Figs. 9 and 10 show a ruler H`similar in construction to the ruler E shown in Fig. 6, except that thebody of the' rulerisV provided with two transverse dovetail slots 36adjacent the ends of the ruler in addition to the longitudinallyextending slots, thereby positively holding the strips againstlengthwise movement. If desired the longitudinal slots may be omittedentirely and transverse slots employed alone. They may be formed alongthe entire length of the ruler rather than at the ends only, as shown.

i Another method of securing the edge Empa' tothe beveled parts of theniler body is by riveting the same thereto, either with orwihout theaddition of vother means forfmechanically interlocking the parts. Figs.11 andv12 show a ruler I, the edge strips 4l and 4I of which are rivetedto the beveled edges of the ruler body by metal rivets 42 locatedadjacent the ends of the ruler. As shown, the rivets 42 are supplementedby a mechanical interlock similar vto that shown Y in Fig. 6.. In someinstances it may be desirable to have the heads of the rivets embeddedin the edge strip as shown'in Figs. 13 and 14, wherein the ruler isdesignated generally by the reference character J, and' the rivets, theupper ends of which are-embedded in the edge strips 43 and 44, by thereference character 45.

A still further modified construction is shown' in Figs. 15 and 16. Theruler K shown in these figures is similar in construction. to that shownin Fig. 6 except that the mechanical interlock shown in Fig. 6 -issupplemented by projections .46 formed integral with the edge strips 41and 48 adjacent the ends thereof, which projections extend into holes in'the beveled edges 'of the ruler body. The'holes are counterbored orbeveled from the Vbottom and the result is a rivet formed integralwiththe edge strips. .It will be understood that, inthe present instance aswell as in themodiflcations illustrated in Figs. 11 and 13, rivets may be employed throughout the en- In the construction shown in Figs. 4, 5,6, and

9 to 16, the edges of the ruler bodies extend .or project to some extentunderneath the edge strips. .This construction gives added support tothe .edge strip and protects the under metal surface of the body portiontherebetween, but is not Asuitable when it is desired to employtransparent edge strips having graduations on the under surface. Inthelatter event the construction shown in Figs. '7 vand 8 is preferred.

The edge strips which are made of a plastic are A,with all formscf myinvention applied to the ruler bodiesv by molding under heat and pres,-sure, and as previously stated, the graduations can be simultaneouslyfmolded therein during their formation. During the molding operation theplastic flows into the interlock grooves, etc. in the ruler body andbecomes cemented thereto forming a strong mechanical connectiontherebetween. d Y l From the foregoing description of the preferredembodiments of the invention it will be apparent 'that the objectsheretofore enumerated have been accomplished, and that a novel draftingruler has been,V provided. While the preferred embodiments of theinvention have been illustrated and described, I do not wish to belimited to the construction shown which may be varied within the scopeof this invention.

It is my intention to cover all variations, adapta'- tions and usesthereof that come within the' mismos? 3 body having a top beveled edgeportion tapering of said edge strip engaging within the groove on voutwardly and provided with grooves in the upper the upper side of saidbeveled edge portion, and

and the lower sides thereof, s V-shaped edge a tongue on the upper sideof the under prong strip engaging around said beveled edge portion ofsaid edge strip engaging within the groove on 5 and formed from aplastic molded in position, the underside of said beveled edge portion.

a tongue on the underside oi the upper prong CHARLES H. LITTLE.

